I believe I have found the perfect, modern theory of consciousness, completely supported by every study yet done on the matter!
"We really don't know what's going on. More research is needed. But there's probably no magic involved."
Hmm. My comment is the most highly upvoted response to your survey at the moment, and the second highest upvoted one is by XiXiDu expressing basically the same position as mine, but I don't see it on your list. Here's a summary: we don't yet have enough insight to choose any specific answer or even to know if we're asking the right questions. We're facing an unsolved scientific problem. The wisdom of crowds doesn't apply here. If no one has yet discovered Maxwell's equations or Watson and Crick's double helix, no amount of surveying can lead you to the right answer. You have to do, like, actual math and physics and biology and stuff.
I don't like statements like "we can never know" this or that. For example, you can convince everyone that quantum immortality works by killing them along with yourself. (This shouldn't pose any risk if you've already convinced yourself :-) Paul Almond has proposed that this can solve the Fermi paradox: we don't see alien civilizations because they have learned to solve complex computational problems by civilization-level quantum suicide, and thus disappeared from our view.
It seems probable to me that if we think a little harder, we can figure out a way to investigate observer-dependent statements scientifically.
To me, the empirical evidence in support of the existence of qualia is so clear and so immediate that I can't figure out what you're not seeing so that I can point to it.
I ... don't think there's much empirical support for the actual existence of the painfulness of pain. Sure, humans experience pain in very similar ways, and you can lump all those experiences into the category pain, and talk about what characteristics are present in all the category members, but those common characteristics aren't a physical object somewhere called painfulness.
As for h...
You've missed a major position: that the entire idea of "substrate independence" is a red herring. Detecting the similarity of two patterns is something that happens in your brain, not something that's part of reality.
This whole thing, AFAICT, is an attempt to have an argument war, rather than an attempt to understand/find truth. It is possible that no position on this subject makes any sense whatsoever, for example.
Or, to put it another way, failure to offer a coherent refutation of an incoherent hypothesis doesn't represent evidence for the incoherent hypothesis.
Maybe I should clarify a bit. I have two intuitions about the relation of consciousness and calculation. The first is that abstract existence of a computation, in the mathematical sense (where "X exists" basically means that the definition of X is free of contradictions), doesn't guarantee consciousness. The computations should be physically implemented somewhere, by which I mean there should be a physical structure isomorphic to the abstract process of computation.
The second intuition is that the specific qualities of consciousness should be inv...
I have no objection to this position. However, it does not imply substrate independence, and strongly suggests its negation.
I disagree, and think that in any case substrate independence is of two types. The directions are: replacing basic units with complex units and replacing complex units with other complex units. Replacing basic units with complex units that do the same thing the basic unit did preserves equations that treated the basic unit as basic. I will attempt to explain.
Consciousness is presumably not a unique property of one specific system. ...
I'll accept option #2 as close enough to my view.
Wrt necessitating an "algorithms" view for q5... maybe. My initial answer there was to observe confusion, either in myself or the question, precisely in the area you point out here: it's unclear how the labels "input" and "output" map to anything we're talking about. I don't reject your proposed mapping, but I don't find it especially compelling either. I'm not sure that those labels necessarily do mean anything, actually.
Wrt not implying substrate independence: sure, I agree ...
I guess the only quibble I would have, and I don't know that it really changes your critique much, is that I wrote that neurons would be some sort of gate equivalent. I wouldn't say that neurons have a simple gate model (that they're simply an AND or an XOR, for instance). But I do see them as being in some sense Boolean. Anyway, I would just try to clarify my fairly short answer to say that I believe that computation can always be broken down into smaller Boolean steps, and these steps could be rendered in many different media.
Computationality in any fas...
the Kolmogorov complexity of a definition of an equivalence relation which tells us that an AND gate implemented in a MOSFET is equivalent to an AND gate implemented in a neuron is equivalent to an AND gate implemented in desert rocks
Isn't that only a problem for those who answer "functions" to question 5? Desert-rocks-AND-gate and MOSFET-AND-gate are functionally-equivalent by definition, but if you're not excluding side-effects it's obvious that they're not computationally equivalent.
Edit: zaph answered algorithms, so your counter-argument doesn't really target him well.
I wonder if I'm a qualia skeptic. I think that qualia are Humean impressions, the most "forceful and vivacious" contents of the mind. Dan Dennett has recently revived this view (without sufficiently crediting Hume, sadly); at one point he calls it the fame model of consciousness. What makes a thought conscious is that it does a lot; it has a very rich variety of interactions with other things going on in the mind.
This explains why there can be perception without consciousness; the much discussed (by philosophers) case of blindsight is an examp...
Yesterday, as a followup to We are not living in a simulation, I posted Eight questions for computationalists in order to obtain a better idea of what exactly my computationalist critics were arguing. These were the questions I asked:
- As it is used in the sentence "consciousness is really just computation", is computation:
a) Something that an abstract machine does, as in "No oracle Turing machine can compute a decision to its own halting problem"?
b) Something that a concrete machine does, as in "My calculator computed 2+2"?
c) Or, is this distinction nonsensical or irrelevant?- If you answered "a" or "c" to question 1: is there any particular model, or particular class of models, of computation, such as Turing machines, register machines, lambda calculus, etc., that needs to be used in order to explain what makes us conscious? Or, is any Turing-equivalent model equally valid?
- If you answered "b" or "c" to question 1: unpack what "the machine computed 2+2" means. What is that saying about the physical state of the machine before, during, and after the computation?
- Are you able to make any sense of the concept of "computing red"? If so, what does this mean?
- As far as consciousness goes, what matters in a computation: functions, or algorithms? That is, does any computation that give the same outputs for the same inputs feel the same from the inside (this is the "functions" answer), or do the intermediate steps matter (this is the "algorithms" answer)?
- Would an axiomatization (as opposed to a complete exposition of the implications of these axioms) of a Theory of Everything that can explain consciousness include definitions of any computational devices, such as "and gate"?
- Would an axiomatization of a Theory of Everything that can explain consciousness mention qualia?
- Are all computations in some sense conscious, or only certain kinds?
I got some interesting answers to these questions, and from them I can extract three distinct positions that seem consistent to me.
Consistent Position #1: Qualia skepticism
Perplexed asserted this position in no uncertain terms. Here's my unpacking of it:
"Qualia do not exist. The things that you're confused about and are mistaking for qualia can be made clear to you using an argument phrased in terms of computation. When you talk about consciousness, I think I can understand your meaning, but you aren't referring to anything fundamental or particularly well defined: it's an unnatural category."
The internal logic of the qualia skeptic's position makes sense to me, and I can't really respond to it other than by expressing personal incredulity. To me, the empirical evidence in support of the existence of qualia is so clear and so immediate that I can't figure out what you're not seeing so that I can point to it. However, I shouldn't need to bring you to your senses (literally!) on this in order to convince you to reject Bostrom's simulation argument, albeit on grounds completely different than any I've argued so far. If you don't buy that there's anything fundamental behind consciousness, then you also shouldn't buy Bostrom's anthropic reasoning in which he conjures up the reference class of "observers with human-type experiences"; elsewhere he refers to "conscious experience" and "subjective experience" without implication that he means anything more specific. That's taking an unnatural category and invoking it magically. In the statement that we are something selected with uniform probability from that group, how do you make sense of "are"?
Consistent Position #2: Computation is implicit in physics
This position is my best attempt at a synthesis of what TheOtherDave, lessdazed, and prase are getting at. It's compatible with position #1, but neither one entails the other.
To understand this position, it is helpful, but not necessary, to define the laws of physics in terms of something like a cellular automaton. Each application of the automaton's update rule can be understood as a primitive operation in a computation. When you apply the update rule repeatedly on cells nearby each other, you're building up a more complex computation. So, "consciousness is just computation" is equivalent in meaning, essentially, to "consciousness is just physics".
This position more-or-less necessitates answering "algorithms" to question #5, or if not that then at least something similar to RobinZ's answer. If you say "functions" then you at least need to explain how to reify the concepts of "input" and "output". You can pull this off by saying that the update rules are the functions, the inputs are the state before the rule application, and the outputs are the state afterward. Any other answer probably means you're taking something closer or identical to position #3 which I'll address next. This comment by peterdjones and his followups to it provide a (Searlesque) intuition pump showing other reasons why a "functions" reply is problematic.
I have no objection to this position. However, it does not imply substrate independence, and strongly suggests its negation. If your algorithmic primitives are defined at the level of individual update-rule applications, then any change whatsoever to an object's physical structure is a change to the algorithm that it embodies. If you accept position #2 while rejecting position #1, then you may actually be making the same argument that I am, merely in different vocabulary.
Consistent Position #3: Computation is reified by physics
I was both shocked and pleased to see zaph's answer to question #6, because it bites a bullet that I never believed anyone would bite: that there is actually something fundamental in the laws of physics which defines and reifies the concept of computation in a substrate-independent fashion. I can't find any inconsistency in this, but I think we have good reason to consider it extremely implausible. In the language of physics which is familiar to us and has served us well — the language whose vocabulary consists of things like "particle" and "force" and "Hilbert space" — the Kolmogorov complexity of a definition of an equivalence relation which tells us that an AND gate implemented in a MOSFET is equivalent to an AND gate implemented in a neuron is equivalent to an AND gate implemented in desert rocks, but is not equivalent to an OR gate implemented in any of those media — is enormous. Therefore, Solomonoff induction tells us that we should assign vanishingly low probability to such a hypothesis.
I hope that I've fairly represented the views of at least a majority of computationalists on LW. If you think there's another position available, or if you're one of the people I've called out by name and you think I've pigeonholed you incorrectly, please explain yourself.